Folding knife



FIG. 1 is a perspective view of a folding knife showing our new design;

FIG. 2 is a first side elevation view thereof;

FIG. 3 is a second side elevation view thereof;

FIG. 4 is a front elevation view thereof;

FIG. 5 is a rear elevation view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a second perspective view thereof. 

CLAIM The ornamental design for a folding knife, as shown and described. 